Etching apparatus for edges of substrate

ABSTRACT

An etching apparatus comprises a chamber; a substrate supporter in the chamber; a substrate disposed on the substrate and having one of a notch zone and a flat zone, the substrate having a rim of a circular shape except in the one of the notch zone and the flat zone, wherein the rim of the substrate has a dented shape in the notch zone and a chord shape in the flat zone; a substrate-screening unit having a substantially same shape as the substrate and disposed over the substrate, the substrate-screening unit having a portion corresponding to the one of the notch zone and the flat zone, wherein the substrate-screening unit has a first diameter smaller than or equal to a second diameter of the substrate; a gas injection means supplying gases onto a periphery of the substrate; and a power supply unit supplying an RF (radio frequency) power into the chamber.

The present invention claims the benefit of Korean Patent Application No. 2006-105829 filed on Oct. 30, 2006, which is hereby incorporated by references.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate processing apparatus for manufacturing semiconductor devices or liquid crystal display devices, and more particularly, to an etching apparatus for removing thin films or particles of edges of a substrate.

2. Discussion of the Related Art

In general, a semiconductor device or a flat panel display device is fabricated by depositing thin films on a surface of a substrate, such as wafer or glass, and then etching the thin films to thereby form thin film patterns.

During a deposition step of a thin film, the thin film is deposited substantially on an entire surface of the substrate. However, during an etching step of the thin film using an etching mask, the thin film is mainly etched on a central area of the substrate. Therefore, at edges of the substrate, the thin film may remain, and by-products or particles, which may be generated during the etching step, may accumulate. If next steps progress without removing such a thin film or particles accumulated at the edges of the substrate, the thin film or particles may peel off and may contaminate other areas of the substrate. Or the substrate may bend and may be misaligned.

To solve the problems, recently, an additional process of etching the edges of the substrate has been performed particularly in manufacturing semiconductor devices.

A method of etching the edges of a substrate is divided into wet-etching using etchant and dry-etching using plasma generated by gases. FIG. 1 illustrates an etching apparatus for edges of a substrate using plasma according to the related art.

A related art etching apparatus 100 includes a chamber 10 defining a reaction space, a substrate supporter 20 disposed in the chamber 10, and a gas distribution plate 30 disposed over the substrate supporter 20 and having a plurality of injection holes 32. The gas distribution plate 30 seals up an upper wall of the chamber 10. An exhaust line 12 is connected to a lower part of the chamber 10. The substrate supporter 20 is movable up and down by an up-and-down driving unit 70. To expose edges of a substrate S to plasma, the substrate supporter 20 may have a smaller diameter than the substrate S.

The injection holes 32 are disposed along a periphery of the gas distribution plate 30 and are connected to an etching gas supply line 40, thereby injecting etching gases only around the edges of the substrate S. The etching gas supply line 40 is connected to an etching gas supply unit 50.

Further, an inert gas supply line (not shown) may be connected to a central portion of the gas distribution plate 30. The inert gas supply line may inject inert gases when the edges of the substrate S are etched, and thus a central portion of the substrate S may be prevented from being etched.

Meanwhile, a substrate-screening unit 31 protrudes from a bottom surface of the gas distribution plate 30. The substrate-screening unit 31 covers the central portion of the substrate S and makes only the edges of the substrate S exposed to plasma. The substrate-screening unit 31 may be formed as one body with the gas distribution plate 30 or may be separately formed and then attached to the gas distribution plate 30. The substrate-screening unit 31 has a symmetrical shape to the substrate supporter 20 and has a diameter smaller than or equal to the substrate S.

An RF (radio frequency) power source 60 is electrically connected to the substrate supporter 20, and an impedance matching system 62 is disposed between the substrate supporter 20 and the RF power source 60.

Hereinafter, an etching method of edges of a substrate using the related art etching apparatus 100 will be described with reference to FIG. 2. FIG. 2 illustrates the etching apparatus in a process of etching the edges of the substrate according to the related art.

First, the substrate S is carried into the chamber 10 through a gate (not shown) and is disposed on the substrate supporter 20. The chamber 10 is under a vacuum condition by a vacuum pumping, and the substrate supporter 20 is raised to a process position by the up-and-down driving unit 70 as shown in FIG. 2. At this point, the substrate supporter 20 may be raised to a position such that a distance between the substrate S and the substrate-screening unit 31 may be within a range of about 0.2 mm to 0.5 mm. This is why radicals or ions of plasma generated at the edges of the substrate S are prevented from being diffused into the central portion of the substrate S and badly affecting a thin film pattern already formed on the central portion of the substrate S.

After raising the substrate supporter 20 to the process position, etching gases are injected through the injection holes 32 at the periphery of the gas distribution plate 30, and simultaneously, an RF power is applied to the substrate supporter 20 from the RF power source 60, whereby plasma is generated around the edges of the substrate S. The radicals or ions in the plasma etch and remove a thin film formed at the edges of the substrate S.

On the other hand, recently, an edge portion of the substrate S is grooved to form a notch zone 45. The notch zone 45 is utilized for exact alignment, as shown in FIG. 3. When the edges of the substrate S is etched using the etching apparatus in FIG. 2 including the substrate-screening unit 31, which has a smaller diameter than the substrate S, an inner side surface of the notch zone 45 is screened by the substrate-screening unit 31 such that thin films or particles on an inner side surface of the notch zone 45 are not etched. An area of the notch zone 45 screened by the substrate-screening unit 31 is defined as a screened area 47. Namely, thin films or particles P on the side surface of the notch zone 45 in the screened area 47 are not etched and remain after the etching process using the related art etching apparatus, as shown in FIG. 4.

FIG. 5 shows a vision picture of a notch zone after etching process using an etching apparatus according to the related art. As shown in FIG. 5, an inner surface of the notch zone is not etched such that thin films or particles remain after etching process. As explained above, if next steps progress without removing such a thin film or particles accumulated at the edges of the substrate, the thin film or particles may peel off and may contaminate other areas of the substrate. Or the substrate may bend and may be misaligned.

On the other hand, when a small size substrate, which has a diameter less than 200 mm, is used, an edge portion of the substrate is cut to form a flat zone instead of being grooved to form the notch zone. In this case as forming the notch zone, an inner side surface of the flat zone is screened by the substrate-screening unit such that thins films or particles on an inner side surface of the notch zone 45 are not etched.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an etching apparatus that effectively etches edges of a substrate having one of a notch zone and a flat zone.

An object of the present invention is to provide an etching that effectively removes thin films or particles on edges of a substrate having one of notch zone and a flat zone with a substrate-screening unit having a portion corresponding the one of notch zone and the flat zone.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, an etching apparatus comprises a chamber; a substrate supporter in the chamber; a substrate disposed on the substrate and having one of a notch zone and a flat zone, the substrate having a rim of a circular shape except in the one of the notch zone and the flat zone, wherein the rim of the substrate has a dented shape in the notch zone and a chord shape in the flat zone; a substrate-screening unit having a substantially same shape as the substrate and disposed over the substrate, the substrate-screening unit having a portion corresponding to the one of the notch zone and the flat zone, wherein the substrate-screening unit has a first diameter smaller than or equal to a second diameter of the substrate; a gas injection means supplying gases onto a periphery of the substrate; and a power supply unit supplying an RF (radio frequency) power into the chamber.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 illustrates an etching apparatus for edges of a substrate using plasma according to the related art;

FIG. 2 illustrates the etching apparatus in a process of etching the edges of the substrate according to the related art;

FIG. 3 is a schematic plane view showing a substrate being screened by a substrate-screening unit according to the related art;

FIG. 4 shows a notch zone of a substrate after etching process using an etching apparatus according to the related art;

FIG. 5 shows a vision picture of a notch zone after etching process using an etching apparatus according to the related art;

FIG. 6 is a schematic perspective view showing a substrate-screening unit for an etching apparatus according to an embodiment of the present invention;

FIG. 7 illustrates a substrate-screening unit and a substrate supporter for an etching apparatus according to the present invention;

FIG. 8 is a schematic plane view showing a substrate being screened by a substrate-screening unit according to the present invention;

FIGS. 9A to 9C respectively show a vision picture of a notch zone of a substrate after etching process using an etching apparatus including a substrate-screening unit according to the present invention; and

FIG. 10 is a schematic perspective view showing a substrate-screening unit for an etching apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred exemplary embodiments, examples of which are illustrated in the accompanying drawings.

In the present invention, other elements except for a substrate-screening unit are similar to elements shown in FIG. 1. Accordingly, explanation to the present invention is focused on the substrate-screening unit.

FIG. 6 is a schematic perspective view showing a substrate-screening unit for an etching apparatus according to an embodiment of the present invention. The substrate-screening unit 200 includes a concave portion 230 at a side thereof. The concave portion 230 corresponds to a notch zone of a substrate. Due to the concave portion 230 of the substrate-screening unit 200, problems in the related art because of a notch zone are overcome. Namely, since the substrate-screening unit 200 includes the concave portion 230, which is formed at a side of the substrate-screening unit 200 and corresponding to the notch zone of the substrate, thin films or particles on an inner side surface in the notch zone of the substrate are etched.

The substrate-screening unit 200 according to the present invention includes a first body 210 and a second body 220. The first and second bodies 210 and 220 have a cylindrical shape. The first body 210 has a smaller diameter than the second body 220. The concave portion 230 is formed at the side of the second body 220. The first and second bodies 210 and 220 may be formed as one body or may be separately formed and then attached to each other. The substrate-screening unit may have a single cylindrical body. However, when the substrate-screening unit 230 includes the first body 210 and the second body 220 protruding from the first body 210 to sides, plasma generated at the edges of the substrate is effectively prevented from being diffused into a central portion of the substrate and badly affecting thin film patterns on the central portion of the substrate. Because the second body 220 faces and becomes close to the substrate, a lower surface of the second body 220 is finely flattened. However, other surfaces of the second body 220 are not required to be finely flattened.

FIG. 7 illustrates a substrate-screening unit and a substrate supporter for an etching apparatus according to the present invention.

A substrate S is disposed on a substrate supporter 250, and a substrate-screening unit 200 including a first body 210 and a second body 220 is disposed over the substrate S when an etching process is performed. A lower substrate of the second body 220 faces the substrate S. The substrate supporter 250 has a smaller diameter than the substrate S. Also, the second body 220 of the substrate-screening unit 200 has a smaller diameter than the substrate S. The diameter of the substrate supporter 250 is smaller than or equal to that of the second body 220 of the substrate-screening unit 200. Centers of the substrate S and the substrate supporter 250 correspond to each other. Moreover, the substrate-screening unit 200 is disposed over the substrate S for the concave portion 230 of the second body 220 to correspond to the notch zone 245 (of FIG. 8) of the substrate S. Although not shown, the substrate supporter 250 is disposed in a reaction space of a chamber of an etching apparatus according to the present invention. When the substrate S is disposed on the substrate supporter 250 and the substrate-screening unit 200 comes to be close to the substrate S, an etching gases are injected through injection holes at a periphery of a gas distribution plate, and simultaneously, an RF power is applied to the substrate supporter 250, whereby plasma is generated around the edges of the substrate S. Radicals or ions in the plasma etch and remove a thin film or particles formed at the edges of the substrate S. The substrate-screening unit 200 protrudes from the gate distributing plate to the substrate S.

FIGS. 8A and 8B are schematic plane views showing a substrate being screened by a substrate-screening unit according to the present invention, respectively.

Referring to FIG. 8A, a side of the substrate S is grooved to form the notch zone 245, and a side of the substrate-screening unit 200 is also grooved to form the concave portion 230. In other words, the substrate S has a rim of a circular shape except the notch zone 245, and the rim of the substrate S has a dented shape in the notch zone 245. And the substrate-screening unit 200 has the substantially same shape as the substrate S, and the notch zone 245 of the substrate S and the concave portion 230 of the substrate-screening unit 200 also have the substantially same shape, for example, a semicircular shape. When the substrate-screening unit 200 is disposed over the substrate S, the concave portion 230 of the substrate-screening unit 200 corresponds to the notch zone 245 of the substrate S. The notch zone 245 of the substrate S has a first width W1 and a first depth D1, and the concave portion 230 of the substrate-screening unit 200 has a second width W2 smaller than the first width W1 and a second depth D2 smaller than the first depth D1. Although not shown, the width and the depth of the concave portion of the substrate-screening unit may be equal to the width and the depth of the notch zone of the substrate, respectively.

FIGS. 9A to 9C respectively show a vision picture of a notch zone of a substrate after etching process using an etching apparatus including a substrate-screening unit according to the present invention.

FIG. 9A shows a vision picture of a notch zone of a substrate after etching using an etching apparatus including a substrate-screening unit, which has a concave portion 230 of a width of about 2 mm and a depth of about 1 mm. Thin films or particles of the substrate within a width of about 1.503 mm and a depth of about 1.52 mm are experimentally etched. In FIG. 9A, the etching area of the substrate has a difference from the concave portion 230 of the substrate-screening unit. With respect to the width, the etching area of the substrate is small by 0.479 mm as much as the concave portion 230 of the substrate. On the other hand, with respect to the depth, the etching area of the substrate is great by 0.52 mm as much as the concave portion 230 of the substrate.

FIG. 9B shows a vision picture of a notch zone of a substrate after etching using an etching apparatus including a substrate-screening unit, which has a concave portion 230 of a width of about 4 mm and a depth of about 2 mm. Thin films or particles of the substrate within a width of about 3.711 mm and a depth of about 2.591 mm are experimentally etched. In FIG. 9B, the etching area of the substrate also has a difference from the concave portion 230 of the substrate-screening unit. With respect to the width, the etching area of the substrate is small by 0.289 mm as much as the concave portion 230 of the substrate. On the other hand, with respect to the depth, the etching area of the substrate is great by 0.59 mm as much as the concave portion 230 of the substrate.

FIG. 9C shows a vision picture of a notch zone of a substrate after etching using an etching apparatus including a substrate-screening unit, which has a concave portion 230 of a width of about 8 mm and a depth of about 2 mm. Thin films or particles of the substrate within a width of about 7.46 mm and a depth of about 2.654 mm are experimentally etched. In FIG. 9A, the etching area of the substrate also has a difference from the concave portion 230 of the substrate-screening unit. With respect to the width, the etching area of the substrate is small by 0.54 mm as much as the concave portion 230 of the substrate. On the other hand, with respect to the depth, the etching area of the substrate is great by 0.65 mm as much as the concave portion 230 of the substrate.

Consequently, when the edges of the substrate is etched using the substrate-screening unit including the concave portion having a width and a depth, an etching area of the substrate has a smaller width and a greater depth than the concave portion. Namely, it is know that the width and depth of the concave portion has a close relationship with an etching area of the substrate. Accordingly, the width and the depth of the concave portion of the substrate-screening unit are determined depending on a width and the depth of the notch zone of the substrate.

Referring to FIG. 8B, a side of the substrate S is grooved to form the notch zone 245, and a side of the substrate-screening unit 200 is also grooved to form the concave portion 230. The concave portion 230 of the substrate-screening unit 200 has the substantially same shape as the notch zone 245 of the substrate S. Unlike the substrate-screening unit 200 in FIG. 8A, the concave portion 230 has a fourth width W4 greater than a third width W3 of the notch zone 245 of the substrate S and a fourth depth D4 smaller than a third depth D3 of the notch zone 245 of the substrate S. As know from FIGS. 9A to 9C, when a substrate is etched with a substrate-screening unit having a concave portion, which has a pre-determined width and a pre-determined depth, an etching region of the substrate has a smaller width and a greater depth than the concave portion. Accordingly, although the concave portion 230 has the fourth depth D4 smaller than the third depth D3 of the notch zone 245, an inner side portion of the notch zone 245 is etched. Moreover, although the concave portion 230 has the fourth width W4 greater than the third width W3 of the notch zone 245, a peripheral portion of the substrate, which is covered with the substrate-screening unit 200, is not etched. As a result, a desired etching region is obtained on the substrate S.

FIG. 10 is a schematic perspective view showing a substrate-screening unit for an etching apparatus according to an embodiment of the present invention.

Referring to FIG. 10, the substrate-screening unit 300 includes a first body 310 and a second body 320 like the substrate-screening unit in FIG. 6. In FIG. 10, the substrate-screening unit 300 has a flat side portion 330. The substrate S has a flat zone 345 for exact alignment like the notch zone 245 (of FIGS. 8A and 8B). The substrate S has a rim of a circular shape except the flat zone 345, and the rim of the substrate S has a chord shape in the flat zone. The substrate-screening unit 300, particularly the second body, has the substantially same shape as the substrate S, and the flat side portion 330 has the substantially same shape as the flat zone 345. When the substrate-screening unit 300 is disposed over the substrate S, the flat side portion 330 of the substrate-screening unit 300 corresponds to the flat zone 345 of the substrate S. Due to the flat side portion 330 of the substrate-screening unit 300, thin films and particles on a flat region 355, which corresponds to a side and edges of the substrate S formed because of the flat zone 345, of the substrate S can be etched.

In the etching apparatus according to the present invention, side surfaces or edges, which are generated by forming the notch zone or the flat zone, on the substrate is effectively etched because the substrate-screening unit has the concave portion corresponding to the notch zone or the flat side portion corresponding to the flat zone.

Accordingly, a problem, which is caused by remaining thin films and particles on an inner side surface in the notch zone or the flat zone, is prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the apparatus without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. An etching apparatus, comprising: a chamber; a substrate supporter in the chamber; a substrate disposed on the substrate and having one of a notch zone and a flat zone, the substrate having a rim of a circular shape except in the one of the notch zone and the flat zone, wherein the rim of the substrate has a dented shape in the notch zone and a chord shape in the flat zone; a substrate-screening unit having a substantially same shape as the substrate and disposed over the substrate, the substrate-screening unit having a portion corresponding to the one of the notch zone and the flat zone, wherein the substrate-screening unit has a first diameter smaller than or equal to a second diameter of the substrate; a gas injection means supplying gases onto a periphery of the substrate; and a power supply unit supplying an RF (radio frequency) power into the chamber.
 2. The apparatus according to claim 1, wherein the substrate-screening unit comprises: a first body; and a second body having the first diameter greater than a diameter of the first body, wherein the portion of the substrate-screening unit is formed at a side of the second body.
 3. The apparatus according to claim 2, wherein the first and second bodies are integrated as a single body.
 4. The apparatus according to claim 1, wherein when the substrate has the notch zone, the portion of the substrate-screening unit has a greater width and a smaller depth than the notch zone.
 5. The apparatus according to claim 1, wherein when the substrate has the notch zone, the portion of the substrate-screening unit has a smaller width and a smaller depth than the notch zone.
 6. The apparatus according to claim 1, wherein the gas injection means is disposed on an upper side of the chamber to seal up the chamber, and the substrate-screening unit protrudes from the gas injection means toward the substrate.
 7. The apparatus according to claim 6, wherein the gas injection means includes a plurality of gas injection holes disposed at sides of the substrate-screening unit.
 8. The apparatus according to claim 1, wherein the gas injection means is movable up and down.
 9. The apparatus according to claim 1, wherein the substrate supporter has a third diameter smaller than the second diameter.
 10. The apparatus according to claim 9, wherein the third diameter is smaller than or equal to the first diameter. 